1. Field of the Invention
The present invention relates to a head supporting arm and a method for fabricating it. More particularly, the present invention relates to a structure of a head supporting arm for preventing a read/write head from being damaged during a heating process for bonding a slider to a flexure and relates to a method for fabricating the head supporting arm while preventing the read/write head from being damaged during the heating process.
2. Description of the Prior Art
In an assembly or a fabrication of a head supporting arm used in a magnetic data recording device, such as a hard disk drive device, a very small slider, a read/write head is attached, or bonded to a flexure by an adhesive, such as a thermosetting resin. FIG. 1 shows a prior head supporting arm 1 which includes an actuator arm 2 which has a pivot point 3 mounted on a frame of the hard disk drive device, a load beam 4, a mount plate 5 connecting the load beam 4 with the actuator arm 2, a flexure 6 attached to the load beam 4, and a slider 7 mounted on the flexure 6. The mount plate 5 and the actuator arm 2 are coupled by a swaging connection 8. The slider 7, the flexure 6, the load beam 4 and the mount plate 5 are called as a head gimbal assembly (HGA).
A flexible tube 9 containing four connecting wires 10 connected to a read/write head 13, such as a MR head, shown in FIG. 2, on the slider 7 is mounted on one of the side edges of the head supporting arm. The tube 9 is fixed to the side edge at plural positions by fixing elements 11. This type of head supporting arm is used in a contact start stop (CSS) scheme in which the slider 7 is landed on an outer landing zone of the surface of a data recording disk, such as a hard disk, when the rotation of the hard disk is stopped during a standby condition. When the rotation of the hard disk is started to read the data from the hard disk or to write the data onto the hard disk, the slider 7 takes off from the landing zone and flies above the hard disk.
The FIG. 2 shows a positional relationship of a front end of the load beam 4, the flexure 6 and the slider 7. A dimple 12 formed on the back surface of the load beam 4 contacts an upper surface of the flexure 6 to realize a gimbal action of the slider 7. In the assembling process, the flexure 6 is fixed on a back surface of the load beam 4, and the slider 7 is attached on a back surface of the flexure 6 by the thermosetting resin 15. The cure of the entire thermosetting resin is performed in an oven. Before the heating in the oven, a laser beam is applied in a small area 16 of the exposed area 14 of the flexure 6 to cure the thermosetting resin in the area 16 for tacking the slider 7 onto the flexure 6. This tack is called as a laser tack. Such laser tack becomes possible in the head supporting arm 1 used in the CSS scheme since the portion 16 is exposed in the such arm 1.
A load/unload scheme has been recently developed in which a member called as a ramp element is fixed at a position outside the hard disk. When the read/write operation is not performed, a front tab of the head supporting arm rides on the ramp element, and when the read/write operation is started, the head supporting arm is moved toward a center of the hard disk, whereby the front tab disengages from the ramp element and the slider flies on the hard disk.
FIGS. 3 and 4 show a prior head supporting arm 21 used in the load/unload scheme. The head supporting arm 21 includes an actuator arm 22 which has a pivot point 23 mounted on a frame of the hard disk drive device, a load beam 24, a mount plate 25 connecting the load beam 24 with the actuator arm 22, a flexure 26 attached to the load beam 24 at coupling points 17, and a slider 27 bonded on the flexure 26. The mount plate 25 and the actuator arm 22 are coupled by a swaging connection 28. A flexible tube 29 containing the four connecting wires 30 connected to the MR head 33 on a thin film 34 is mounted on one of side edges of the head supporting arm 21 by fixing elements 31. The load beam 24 is bent at a bending potion 18. A dimple 32 formed on the back surface of the load beam 24 contacts an upper surface of the flexure 24 to realize the gimbal action of the slider 27.
It is required in the head supporting arm used in the load/unload scheme to provide a front tab 19 on the load beam 24, which rides on the ramp element, not shown, at the standby condition, and to provide an aperture 20 in the load beam 24 through which the connecting wires 30 connected to terminals, not shown, on the thin film 34 pass. As a result, an area 35 exposed through the aperture 20 becomes small, as shown in the FIG. 4, and hence the laser tack technology used in the head supporting arm 1 shown in the FIGS. 1 and 2 can not be used. For this reasons, to bond the slider 27 onto a bonding portion 26A, called as a tongue, of the flexure 26, (1) an instant adhesive, such as a cyanoacrylate adhesive, is used, or (2), in the case of that the thermosetting adhesive is used, the bonding region 26A and the slider 27 fixed on a positioning jig are heated in the heating oven to cure the thermosetting adhesive. Such bonding scheme, however, causes new problems in that the productivity is degraded in the case (2), and a flying height of the read/write head varies depending upon the operating temperature in the housing of the hard disk drive device in the case (1). Such latter problem is caused by the following reasons. A glass transition temperature of the cyanoacrylate adhesive is relatively high, such as eighty degrees centigrade. Accordingly, the cyanoacrylate adhesive keeps its glassy state and indicates a relatively high Young""s modulus in a temperature range below the glass transition temperature. When the temperature reaches the glass transition temperature, the state of the cyanoacrylate adhesive is changed to a rubber like elastic state and indicates a relatively low Young""s modulus. That is, in the temperature range below the glass transition temperature, the slider 27 and the bonding portion 26A of the flexure 26 is firmly or integrally bonded through the glass like cyanoacrylate adhesive. Since a coefficient of expansion of the slider differs from that of the bonding portion 26A, a bimetal effect of the slider 27 and the bonding portion 26a occurs in the temperature range below the glass transition temperature, and such bimetal effect does not occur in the temperature range equal or higher than the glass transition temperature since the rubber like adhesive absorbs the change of expansion, so that the flying height of the read/write head varies in depending upon the operation temperature of the hard disk drive device. In the case that the hard disk drive device is operated in a severe operating atmosphere of a broader temperature range than the temperature range of a normal use, it is necessary to use a structure or material for decreasing the above bimetal effect.
One object of the present invention is to provide an improved head supporting arm for the data recording device operated in the load/unload scheme.
Another object of the present invention is to provide the data recording device including the improved head supporting arm operated in the load/unload scheme.
Another object of the present invention is to provide a method for fabricating or assembling the improved head supporting arm for the data recording device operated in the load/unload scheme.
A head supporting arm in accordance with the present invention comprises:
a load beam;
a flexure including a portion coupled to the load beam and a bonding portion;
a slider bonded on the bonding portion by an adhesive;
wherein the bonding portion of the flexure includes an edge placed on a surface of the slider; and
wherein an exposing aperture, which exposes both a portion of a surface region, including the one edge, of the bonding portion and a portion of the surface of the slider, is formed on the load beam.
A dimple is formed on the load beam to provide a gimbal action of the flexure and the slider, and the exposing aperture is formed on the load beam at a position which is located between the dimple and one edge of the slider which is the opposite side to the other edge of the slider at which a read/write head is attached.
The exposing aperture is formed on the load beam at a position for exposing both a portion of a surface region including one edge of the bonding portion adjacent to the one edge of the slider and a portion of the surface of the slider.
A groove surrounding the portion of the bonding portion exposed by the exposing aperture is formed on the bonding portion.
The groove is formed on the surface of the bonding portion facing to the slider.
The groove is formed on the surface of the bonding portion facing to the load beam.
The groove extends along a semicircular path surrounding the portion exposed by the exposing aperture.
The groove extends along a half rectangular path surrounding the portion exposed by the exposing aperture.
A plurality of apertures surrounding the portion of the bonding portion exposed by the exposing aperture are formed on the bonding portion.
The plural apertures are formed along a semicircular path surrounding the portion exposed by the exposing aperture.
An island like portion including the portion exposed by the exposing aperture is extended from the bonding portion through a neck portion.
A data recording apparatus in accordance with the present invention comprises:
a data recording medium for recording data; and
a head supporting arm relatively moved to the data recording medium;
the head supporting arm comprising:
a load beam;
a flexure including a portion coupled to the load beam and a bonding portion;
a slider bonded on the bonding portion by an adhesive;
wherein the bonding portion of the flexure includes edge placed on a surface of the slider; and
wherein an exposing aperture, which exposes both a portion of a surface region, including the one edge, of the bonding portion and a portion of the surface of the slider, is formed on the load beam.
A method for fabricating a head supporting arm in accordance with the present invention comprises the steps of:
preparing a load beam to which a flexure including a bonding portion is attached, the load beam being formed with an exposing aperture, through a portion of an area of which a portion of a surface region including an edge of the bonding portion is exposed;
applying an thermosetting adhesive on the bonding portion;
positioning the slider to the thermosetting adhesive on the bonding portion to expose a portion of the surface of the slider through a remaining portion of the area of the exposing aperture; and
directing a laser beam to the portion of the surface region of the bonding portion and the portion of the surface of the slider through the exposing aperture to cure the thermosetting adhesive.